Rotary impact breakers



Nov. 14, 1967 P. w. PARKER ROTARY IMPACT BREAKERS z Shets-Sheet 1 Filed Jan. 11, 1965 v f L L a 0 O 0 n b 0 o 0 Nov. 14, 1967 F. w. ARkER 3,352,502

. ROTARY IMPACT BREAKERS Filed Jan 11, 1965 2 Sheets-Sheet z United States Patent Ofifice 3,3525% Patented Nov. 14, 1967 3,352,502 ROTARY IMPACT BREAKERS Frederick William Parker, Leicester, England, assignor to Frederick Parker Limited, Leicester, England, a British company Filed Jan. 11, 1965, Ser. No. 424,736 6 Claims. (Cl. Z41192) ABSTRACT OF TIE DISCLGSURE A rotary impact breaker comprising a casing containing a rotor formed with slots having mounted therein radially adjustable hammers, wherein each hammer is formed with two apertures each alignable with any one of a number of apertures in the rotor at different distances from the rotor axis, and a locking element is inserted into each two aligned apertures to secure the hammer in position, each element being such that, by locating it in two alternative positions, the hammer can be located in two different radial positions for each corresponding aperture in the rotor.

This invention relates to rotary impact breakers for breaking stone or like hard material (hereinafter referred to generically as stone) in the production of, for example, road chippings, material for various grades of concrete aggregate, and so on.

In particular, the invention is concerned with a breaker of the kind comprising a casing in which is mounted at least one shaft carrying a rotor fitted with hammers adapted, on rotation of the rotor, to strike against pieces of stone introduced into the casing, usually at or adjacent the top thereof from a suitable chute or hopper, and to throw the stone against the inner surface of the casing (usually a number of times as it rebounds) so that it is broken up, the pieces of stone, thus reduced in size by impact breaking, then being discharged from the casing, usually through an opening in its bottom.

Now, aswill be appreciated, the distance between the breaking edges of the hammers, i.e. their outer end portions which are disposed outside the confines of the rotor and strike the stone, and the inner surface of the casing in breakers of the. kind concerned is quite critical in order that the speed of the breakin edges is maintained within permissible limits so that the pieces of stone are reduced to the required size, However, the breakin edges of the hammers are subject to very rapid wear and the efiiciency of the breaker very quickly diminishes. It has been pre- VlOllSlY prosposed to make the hammers reversible so that both the opposite end portions of each hammer can be used as-breaking edges. However, only approximately half of each hammer can usually be allowed to wear away with reversal. of the hammers before the performance'of the breaker ecomes detrimentally affectedand the hammers have to be replaced, with the result that approximately half of the material of each hammer is wasted. Moreover, the replacement or reversal of the hammers takes up a considerable time during which, of course, the breaker is inoperative.

An object of the present invention is to obviate these disadvantages.

A further object is to provide a rotary impact breaker in which the hammers can be adjusted individually to compensate for wear of their breaking edges and to enable the latter to be maintained in approximately the same position in relation to the rotor axis and hence to the inner surface of the breaker casing. Thus, an aim is to keep the speed of the breaking edges of the hammers substantially constant throughout the life of the hammers so that the hammers will produce constant stone-breaking results throughout their life.

Another object of the invention is to provide a rotary impact breaker in which there is only a comparatively small wastage of the material of the hammer.

In the rotary impact breaker according to the invention, the rotor has the hammers so mounted therein as to be individually adjustable outwardly in a direction away from the axis of the rotor, whereby the breaking edges of the hammers, notwithstanding wear thereof, can be maintained in approximately the same position in relation to the periphery of the rotor.

In implementing the invention, the hammers, of which there may be two, three, four, six or indeed any appropriate number, and which may be either of curved configuration or generally fiat, may be a sliding fit within slots formed in the rotor so as to be movable outwards with respect to the rotor axis as wear of their breaking edges takes place and may be located and locked in position in the slots, after adjustment, by various means.

During adjustment of the hammers, the inner ends thereof will be moved progressively nearer to the periphery of the rotor. When, therefore, the majority of a hammer has ultimately been worn away and it is necessary to renew it, there only remains a comparatively thin bar of material. Thus, there is less wastage of the material of the hammers. In fact, it is found that approximately one fifth of the hammer only is wasted, and accordingly each hammer has a longer life. In addition, the operational costs are considerably reduced.

The rotor may comprise two spaced end plates which are rigidly fixed on the drive shaft, each perpendicular to the axis of the shaft, and have slots therein which open at the peripheries of the plates and support the side portions of the hammers with the outer end portions of the latter, constituting the breaking edges, projecting beyond the confines of the end plates. Where the hammers are of a substantial length, one or more additional plates may be provided on the drive shaft between the end plates to support the hammers at a position or positions along their lengths.

If necessary the two end plates may be rigidly connected together by longitudinal members extending parallel to the axis of the drive shaft. Preferably, each longitudinal member is arranged alongside a hammer, the member having a flat side surface which is flush with those sides of the slots in the end plates which are remote from the leading, breaking edge of the hammer. Thus, each hammer bears against this flat surface of the member concerned. A plate for protecting the rotor adjacent the breaking face of each hammer may be mounted on the outer periphery of the rotor so as to extend across and adjacent to the breaking face.

Details of advantageous ways of implementing the means for securing each hammer in position after outward adjustment thereof are set out below.

A rotor according to the invention employing advantageous hammer-securing means provided by the invention will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a vertical cross section through a conventional form of rotary impact breaker showing it equipped with a rotor according to the invention,

FIGURE 2 is a general perspective view of this rotor with parts cut away and parts in an exploded form,

FIGURE 3 is a front view of the upper part of this rotor taken in the direction of arrow III in FIGURE 2,

FiGURE 4 is a cross section through the upper part of the said rotor taken on the line lV-1V of FIGURE 3,

Referring first to FIGURE 1 of the drawings, this shows the basic construction of a conventional rotary impact breaker of the kind concerned. This comprises a casing 1 the roof of which is formed by breaker bars and which has at the top thereof an inlet 2 and at the bottom thereof an outlet 3. Rotatably mounted in the casing is a shaft 4 carrying a rotor 5 fitted with hammers 6. The shaft 4 is driven in an anti-clockwise direction as viewed in this figure by drive means of known form (not shown), and the arrangement is that pieces or stone fed into the casing via the inlet 2 are carried around by the hammers 6 and thrown against the breaker bars forming the roof of the casing 1. As the pieces of stone rebound from the breaker bars they are repeatedly thrown back by the hammers until, thereby reduced in size, they are discharged through the outlet 3.

The rotor 5 in each of the four examples comprises two generally flat end plates 7 which are rigidly keyed on the drive shaft 4 perpendicular to the latter. The two end plates 7 are formed with pairs of aligned slots 8 opening at the peripheries of the plates, and the side portions of the hammers 6 are a sliding fit within these slots 8 so that the hammers are movable outwardly in a direction away from the rotor axis. The outer end portions of the hammers project beyond the confines of the end plates 7 and constitute breaking edges.

For convenience, the same reference numerals will be used to denote like parts in the following further description.

Turning to the first example which is illustrated in FIG- URES 2, 3 and 4 and can also be seen in FIGURE 1, each end plate '7 is provided, alongside each slot 8 therein, with a support 9 against which the hammer concerned bears. Formed in each support are three spaced apertures 10 arranged in a line at different radial distances from the rotor axis. The inner end of each of the hammers, which in this case are generally flat and extend radially with respect to the rotor, has two projections 611 located between the end plates and each form-ed with an oval shaped aperture 11 which is tapered in cross section. The two apertures 11 in each hammer are aligned with the two lines of apertures 10 in the associated supports 9. A removable locking pin 12 located in each aperture 11 in the hammer, can be inserted into any one of the apertures 10 in the corresponding support 9. Each locking pin 12 has an oval shaped head which is tapered in cross section and is complementary to and fits in the aperture 11 concerned, and a projecting lug, offset from the centre of the head, for insertion into the selected one of the apertures 19 in the support concerned. The lugs are screw threaded at their outer ends so as to receive nuts 13 which, when tightened down on to the lugs, rigidly secure the hammer to the supports 9. The idea of this arrangement is that, by turning the head of each locking pin 12 relatively to the aperture 11 in the hammer, the projecting lug can be brought into two positions at different radial distances from the rotor axis. Thus, each hammer 6 can be set at two ditferent radial distances from the rotor axis for each aperture 10 in the support 9. Accordingly, there are six positions at different radial distances from the rotor axis in which each hammer can be set after adjustment to compensate for wear of its breaking edge (as shown at 6 in FIGURE 2).

In another example, employing similar hammer-securing means, the end plates may be connected together by a number of longitudinal members, each member being arranged alongside a hammer in the same position as the supports 9 in the previous example. The lines of apertures (corresponding to the apertures 10) for receiving the lugs of the locking pins 12 are formed in these longitudinal members. In this event, there are preferably two lines of such apertures in each member arranged adjacent the respective ends thereof, and, in alignment with these two lines, two apertures in the associated hammer. However, there may, of course, be any number of lines of apertures in each longitudinal member with a corresponding number of apertures in the associated hamme More- 4- over, as in the previous example, there may be any number of apertures in each line in the longitudinal members.

Finally, in the above embodiment, adjustment of the hammers can be easily and rapidly eifected, and to facilitate this the casing of the breaker may be provided with a door which is somewhat larger than in conventional breakers.

I claim:

1. A rotary impact breaker comprising a casing providing with an inlet and an outlet,at least one shaft rotatably mounted in saidcasing, a rotor comprising two spaced end plates rigidly fixed on said drive shaft, each perpendicular to the axis of the latter, and having parallel-sided slots formed therein which extend generally in the outwards direction and open at the peripheries of the plates, hammers mounted in said rotor with their side portions accommodated with a sliding fit in the slots in the end plates, and with their outer end portions, constituting stone-breaking edges, projecting beyond the confines of the end plates, means for individually adjusting the hammers in said slots outwardly in a direction away from the axis of the rotor, and means for locating and securing the hammers in position in the slots after adjustment thereof, whereby the hammers, on rotation of the rotor, strike against pieces of stone fed into the casing through the inlet and throw these pieces against the inner surface of the casing so that they are broken up and reduced in size, the stone then being discharged through the outlet, and the outer end portions of the hammers can, notwithstanding wear thereof, by adjustment of the hammers, be maintained in approximately the same position in relation to the periphery of the rotor, hammer supports on each rotor end plate, each support being arranged alongside one of the slots therein so that the hammer in the slot bears against the support, each support formed with a plurality of spaced apertures arranged in a line at different distances from the rotor axis, each of the hammers formed with apertures each disposed in alignment with one of the lines of apertures in the supports of the hammer, and a removable locking pin located in each aperture in each hammer, this locking pin being inserted into a selected one of the apertures in the corresponding line of apertures in the support concerned thereby to provide a number of positions at difierent distances from the rotor axis in which the hammer can be located and secured, and wherein each of said locking pins has a head for insertion in two diiferent positions into its aperture in the corresponding hammer, and a projecting lug, offset from the center of the head, for insertion into a selected aperture in the corresponding line of apertures in the support concerned, whereby the head of the locking pin can be located in its aperture in the hammer with the projecting lug, located in a selected aperture in the support, at two positions at difierent distances from the rotor axis.

2,. A rotary impact breaker, according to claim 1, wherein the head of each locking pin is oblong in shape and is inwardly tapered towards the face thereof carrying the projecting lug, the corresponding aperture in the hammer being complementan'ly shaped, and the said lug,

is screw threaded and receives a nut for securing the locking pin in position.

3. A rotary impact breaker comprising a casing provided with an inlet and an outlet, at least one shaft rotatably mounted in said casing, a rotor carried by said shaft, at least one hammer fitted in said .rotor and arranged, on rotation of the rotor, to strike against pieces of stone fed into the casing and to throw them against the inner surface of the latter so that they are broken up and reduced in' size, the hammer being mounted with a sliding fit within at least one slot in the rotor so as to be adjustable outwardly in a direction away from the axis of the rotor, whereby the breaking edge of the hammer, notwithstanding wear thereof, can be maintained in approximately the same position inrelation to the periphery of the -rotor, and a removable locking device for securing the hammer in position, characterized in that the rotor is formed with a number of spaced apertures disposed alongside the hammer and arranged at different distances from the axis of the rotor, and the hammer is formed with at least one aperture alignable with any one of the apertures in the rotor, the two aligned apertures receiving a removable locking device which comprises a first part which is located in one of two alternative positions in one of the two aligned apertures, and a second part, offset from the first part, which is located in the other of the two apertures, whereby the hammer can be secured in a number of positions at difference distances from the rotor axis, there being two such positions for each aperture in the rotor obtained by locating the first part of the locking device in its two alternative positions.

4. A rotary impact breaker according to claim 3, wherein the locking device is in the form of an element having a head, constituting the first part of the device, which can be located in two alternative positions in the aperture in the hammer, and, offset from the center of this head, a projecting lug, constituting the second part of the device, which can be located in any one of the apertures in the rotor.

5. A rotor according to claim 4, wherein the head of each locking element is oblong in shape and is inwardly tapered from its outer face towards the inner face carrying the projecting lug, the corresponding aperture in the hammer being complementarily shaped, and the said lug is screw threaded to receive a nut for securing the locking element in position.

6. A rotary impact breaker according to claim 3, wherein the rotor comprises two spaced end plates rigidly fixed on the drive shaft, each perpendicular to the axis of the latter, and having parallel-sided slots formed therein which extend generally in the outwards direction, open at the peripheries of the plates and support the side portions of the hammer with the outer end portion of the latter, constituting the breaking edge, projecting beyond the confines of the end plates, each rotor end plate being provided with a hammer support alongside the slot therein so that the hammer bears against the two supports, each support being formed with a line of spaced apertures arranged at different distances from the rotor axis, and the hammer being formed with two apertures respectively aligned with the said two lines of apertures in the rotor.

References Cited UNITED STATES PATENTS 1,185,619 -6/ 1916 Blum 241-192 2,958,474 11/1960 Meyer 241-192 ANDREW R. JUHASZ, Primary Examiner. 

3. A ROTARY IMPACT BREAKER COMPRISING A CASING PROVIDED WITH AN INLET AND AN OUTLET, AT LEAST ONE SHAFT ROTATABLY MOUNTED IN SAID CASING, A ROTOR CARRIED BY SAID SHAFT, AT LEAST ONE HAMMER FITTED IN SAID ROTOR AND ARRANGED, ON ROTATION OF THE ROTOR, TO STRIKE AGAINST PIECES OF STONE FED INTO THE CASING AND TO THROW THEM AGAINST THE INNER SURFACE OF THE LATTER SO THAT THEY ARE BROKEN UP AND REDUCED IN SIZE, THE HAMMER BEING MOUNTED WITH A SLIDING FIT WITHIN AT LEAST ONE SLOT IN THE ROTOR SO AS TO BE ADJUSTABLE OUTWARDLY IN A DIRECTION AWAY FROM THE AXIS OF THE ROTOR, WHEREBY THE BREAKING EDGE OF THE HAMMER, NOTWITHSTANDING WEAR THEREOF, CAN BE MAINTAINED IN APPROXIMATELY THE SAME POSITION IN RELATION TO THE PERIPHERY OF THE ROTOR, AND REMOVABLE LOCKING DEVICE FOR SECURING THE HAMMER IN POSITION, CHARACTERIZED IN THAT THE ROTOR IS FORMED WITH A NUMBER OF SPACED APERTURES DISPOSED ALONGSIDE THE HAMMER AND ARRANGED AT DIFFERENT DISTANCES FROM THE AXIS OF THE ROTOR, AND THE HAMMER IS FORMED WITH AT LEAST ONE APERTURE ALIGNABLE WITH ANY ONE OF THE APERTURES IN THE ROTOR, THE TWO ALIGNED APERTURES RECEIVING A REMOVABLE LOCKING DEVICE WHICH COMPRISES A FIRST PART WHICH IS LOCATED IN ONE OF TWO ALTERNATIVE POSITIONS 